After diminishing to relatively low numbers following Kim Jong-un’s ascension to power and tighter controls preventing people from leaving the country, the number of defectors reaching South Korea was 15 percent higher between January and July this year as compared to 2015, Chosun Ilbo reports:

From January thorough July this year some 815 North Koreans fled their country and arrived in the South, up around 15 percent from the same period last year, the Unification Ministry said Tuesday.
This suggests that international sanctions and the resulting economic straits in the repressive North are driving many away. More defectors now come from the elite, which for long thrived while ordinary North Koreans starved.
From 2006 to 2011, some 2,000-plus people fled the North every year, but when Kim took power in 2012 numbers dropped to about 1,500.
Last year the number was down to 1,276. The regime boosted border patrols, forcibly relocated the families of defectors, and meted out tougher punishment for those who aided and abetted defections.

To me, the claim that people are leaving in higher numbers because of sanctions sounds very unlikely, to say the least. Even if sanctions are hitting the economy in a way that most people feel (which is itself doubtful at this time), it is difficult to see that it would be enough to tip the scale toward 15 percent more people defecting. One could argue that the speed battles of the past year may well have done much more to lower the quality of life for most North Koreans than sanctions have, but of course, it is impossible to pinpoint a specific reason for this increase.